Motor fuel production



' s. ARMISTEADQJR MOTOR FUEL PRODUCTION July 27, 1943.

Original Filed Oct. 23, 195'? FIG. 3.

FIG.2.

INVENTOR GEORGE ARMISTEAD JR.

BY 4 jwfimw HIS ATTOR NEY the light or intermediate hydrocarbon oil if desired.

2 The conversion products are then separated into vaporsand liquid residue, and the vapors are fractionated to obtain therefrom a suitable condensate above the' motor-fuel boiling range, a motor-fuel. condensate, and a normally gaseous distillate which may be further fractionated to separate therefrom a condensate consisting esT-Iv I.-

' other parts of the system. In heater 3 the cycle "condensate is passed through a sufiicient length sentially of the most easily convertible hydrocarbons such as the C3 and C4 hydrocarbons which may be recycled as described above.

The invention is particularly applicable to. the treatment of a plurality of hydrocarbon fluids' anda 7 intermediate products therefrom such as are obtained by the distillation of crude oil, to effect conversion thereof into motor fuel of high anti-f knock value. For example, crude oil may be fractionated to separate therefrom a gaseous product, a light naphtha condensate, a heavy naphtha condensate, a virgin gasoil condensate and "a 7 heavy oil which maybe a condensate orlreduced Icrude. The gaseousdistillate may be subjected fto further fractionation to'separate' therefrom the most easily convertiblehydrocarbons such as'the V Grand C4 hydrocarbons.

Theheavy naphtha condensate and the virgin gas-oil condensate may .be separately 'treate d under elevated conditiorisof temperature and pressure to effect conversionthereof to motor fuel "of higlr anti-knock value by reforming the heavy naphtha and by severely cracking thevirgin gas Cycle condensate produced in the system "mayfbe separately subjected to elevated condi- "tions of temperature and pressure to effect'crack- 'i ing thereof to motor fuel.

The heavy 'oil or reduced crude obtained from the distillation of'the crude oil and normally gaseous hydrocarbons obtained as: described above, together if desired with similar'hydrocarbons recovered from the system, are then merged with the hot conversion products of one or more of the separate conversion treatments, and the merged products are thereafter subjected to cracking conditions of temperature and pressure I to efiect'cracking of the reduced crudeand'conversion of the normally gaseous hydrocarbons to hydrocarbons within the motorfuel boiling range or to heavier hydrocarbons and 'further 'converskin of the light or"intermediatehydrocarbonoil as desired. 'Products' of the cracking of the L merged materials and other conversion products from'- the system are fractionated to provide a "cycle condensate, a motor fuel condensate, a'nda.

normally gaseous distillate whichmay be recycled to the system preferably after removalcf C2 hydrocarbons and lighter gases.

' The'accompanying drawing illustrates specific embodiments of the methods generally described above. 7 l

Fig. 1 isa diagrammaticyiew-in elevation of apparatussuitable for carrying out the invention *in'a simple application thereof. 7

. Fig. 2 is a diagrammatic view in elevation of apparatus suitable for the applicationlofthe inv vention'to the treatment of a plurality of hy'drm 2 carbon fiuids'fof varying boiling ranges such as are produced by the distillation of crude oil. The

invention willibe described in detail with refer-i fence to the drawing, but-it is to be understood that the-invention is not limited thereby but is capable of other embodiments which maybe beyond the physical limitations of the apparatus findica'ted. v

' In the drawing, referring to Fig; 1,-a light or r.--. intermediate hydrocarbon oil, which may be a 2.. Q p l Y 2,325,093

cycle condensate produced in the system as de scribed below, or which may include a suitable clean hydrocarbon oil introduced into the system through means not shown, ispassed through line *I by means of pump 2 and introduced into the coil of'heater 3 at the'inlet thereof. The oil may be preheated prior to introduction into heater- 3 if desired by means not shown such as direct heating or by heat exchange with hot products from or the coil of heater 3 under elevated conditions oftemperature and pressure and at a velocity wherebysubstantial conversion is effected prior to admixture with other fluids as described below.

Forfexample a clean hydrocarbon oil having an end point of 650 to 750 F. may be heated to a temperatureof 900 to 1050 F. at a pressure of 400 taboo-pounds per square inch fora time sufiicient toeffect maximum conversion without excessive deposition of coke. V

system through line 4 by means of pump 5.1 Line connects with thecoil of heater 3'at one brmo're intermediate ,points thereof whereby the .said

reducedcrude: is merged with the lighter oil, which has been subjected to substantial cracking .be'preheated by suitable meansriot shownprior to introduction into the coil off heater 3.

Simultaneously; there is introduced into the 0011, at the same points of introduction as the reduced, crude or at separate points, gases containing a substantial proportion of convertible normally gaseous hydrocarbons such as Grand C4 hydrocarbons, preferably predominating in the latter. These gases may be passed through line 5 which is'prov'ided withbranches 5m and 5b which connect with the "coil of heater 3 at different points; points of introduction of the normally gaseous hydrocarbons may coin cide with those of the reduccd crudeor maybe spaced apart therefromQ Itt-is, desirable, howeye'r, that the gases be thoroughly admixed with V the strearnfpas'sing through the coil of heater 3 before substantial cracking of the reduced crude isieffected. Opticnally'all or a part of the gases may be; introduced into admixture with the stream of oil prior toheating the latter, for ex ample, through "line '50 "which conects' lines I and ii. The normally gaseous hydrocarbons may consist wholly or in part of cycle stock'or "may include gases producedexternally'of the system and introduced jby v means not shown. Line 5 includes heat;exch angers 6' and l wherebythe normally gaseous hydrocarbons are preheated priorto. introduction into the coil of heater 3,

and other heatingjmeansnotfshown may be provided for furtherpreheating of the normally gaseous hydrocarbons as desired.

. The conversion products from heater 3 are withdrawn therefrom through line 8 provided vwith control valve 9 and are introduced into evaporator lilwherein separationpf tha vapors liquid residue occurs;- Evaporator l0 may 1 provided'with'suitable bafiiing'in the upper portion thereof to effect separation of 'entrained matter fromfthe vapors, if necessary, to permit passage overhead of vaporsincluding asuitable clean; cycle: stock above the motor-fuel boiling range for heater 3. Fractionator 10 may be A 'heavy'hydrocarbon oil which may be a re- V 'duced crude is introduced as fresh feed to the passage through heat exchanger 6 in indirect Contact with the normally gaseous charge to the coil of "heater 3. Additional cooling meansrnay be provided if. desired for cooling thexvapors prior to introduction into 'Iractionator Hi. In

fractionator I4 conditions of temperature and pressure are maintained to effect condensation and separation of hydrocarbons above the motor-fuel boiling range, which condensate is withdrawn through line I for passage to the heater 3, as described above or'withdrawn from the system for'treatment elsewhere by means not shown. For example, fractionator I! may be operated at a pressure of 50 to 250 pounds per square inch with a bottom temperature of 550 to 650 F. and a toptempe'rature of 350 to 425 F. Cooling coil l6 may be provided in the top of fractionator 14 to supply the reflux necessary to eifect the desired fractionation.

The vapors uncondensed in fractionator l4 pass overhead through line H and after being cooled by passage through heat exchanger! in i rect contact with the normally gaseous charge to heater 3 are further cooled and condensed in coil H and enter separator l3 where a separation of liquid and gaseous products takes place. The gaseous products are introduced by means of compresso through line 24 and liquid products are passed through pump line !8 and heat exchanger l8 to an introduct-ion pointnear the top of a fractionator l3. In' fractionator l9 conditions of temperature and pressure are maintained to effect condensation and separation of a substantially stabilized motor fuel which is withdrawn through line provided with control valve 28 and passed through heat exchanger iii. For example, fractionator l9 may be maintained at a pressure of 250 pounds per square inch with a top temperature of 120 F. and a bottom temperature of 300 F. Heating coil 22 and cooling coil 23 may be provided in the bottom and top, respectively, of fractionator 59 to effect the desired fractionation.

The gases unconden sed in fractionator were withdrawn therefrom through line 24' which connects with line E4 which in turn connects with a :fractionator 25 whereby gases from separator l3 and fractionator l'9;-are introduced therein. In fractionator 25 conditions of temperature and pressure are maintained to'effect condensation and separation of the normally gaseous hydrocarbons most suitable for conversion reactions, for example, the C and C4 hydrocarbons. If desired, a portion of the C1 and C2 hydrocarbons may be included in the condensate. Fractionatcr'25 may; for example, he maintained at a pressure of 300 pounds per square inch with a top temperature of F. and a bottom temperature of 120 to 140 F.

Heating means 2? may be provided in the bottom part of fractionator 25 to strip undesired gases from the condensate, and cooling means such as refrigerating coil 23' maybe provided 'in the upper portion of fractionator 25. to main tain the desired fractionation. Uncondensed gases are withdrawn from theupper portion of' 29 provided with Lil tionator 25' throughline 5-b t means of pump 3! and introduced into the coil of heater 3-in the manner described above. However, condensate thus obtained may be. withdrawn from the system .for treatment elsewhereby means not shown oradditional similar normally gaseous hydrocarbons may be introduced to" the system by means notshown for treatment with the condensate withdrawn from fractionator 25.

Preferably, the gases introduced into the coil of heater 3 through line 5 consist essentially of the most easily convertible hydrocarbons. such as C3 and C4 hydrocarbons. However, they may include also lighter hydrocarbons other gases from the system. such as" C2 hydrocarbons, methane and hydrogen. For example, all ore, portion :of the gases withdrawn from the fractionator. l 9. through line 224". maybe diverted froin'line 24 through 1ine33 and introduced di- I rectly into line 5 for passage to heater Valves 34, and 38 in lines 5,."24 and 33, respectively, may be provided to permit the desired distribu tion of the gases through line and fractionator 25. v

ESuitable gas and liquid contact means are provided in towers id, is and 25 to effect the condensation, evaporation, stripping absorption incidental to fractionation.

Referring to Fig. 2, a crude oil or partially topped crude oil introduced to the. system through line 37 by means of pump 3?. maybe preheated in heater 39, for, example to a: temperature of 500 to7-90F. at a pressure of at lnospheric to 1.00 pounds persquare inch. The heatedcrude oil'is then passed througlrline Ml for introduction into crude flash't'ower 52 provided with trap-cut trays .3 and 64. and. coolingmeans 35 at the top thereof to effect fractionation of .thec'rude oil desired. Flash tower 42 is maintained at conditions of temperature and" pressure'to cause vaporization of substantial proportion of' the crude oil and inclusion in the vapors of constituents suitable for drastic craclo .ing treatment and lighter constit ents the production of a reduced crude which collects in The vapors fracwhichcollects in trap-out tray 53. and lighter constituents {132.53 overhead through line 4? providedwith control valve' lli. For example, tower 52 may beoperated'at a pressure" of atmospheric'to 100 pounds per square inch with a top temperatureof 250 to 350 and a bottom temperatureof 550 to 750 F. 1 The heavy naphtha collected in trap-out tray (i3 is withdrawn therefrom through line 49 by, means of pump 50 and introduced into the coil" oi reformlngheater 5! wherein it is subjected to elevated condltions'of temperature and pressure to effect reformingof the heavy naphtha. and

conversion thereof to rnotor fuel of high antiknock value.

Similarly,virgin gas oil collected in trap-out tray M is withdrawntheref in through line by means of-purnp 53 and; introduced intothe inlet of the coil of heater es wherein-the gas oil is subjected to elevated conditions of temperature and pressure to effect substantial cracking thereof to lighter constituents including asubstantial proportion of. 1nctorfucl constituents of high anti-knock value.

similarly. a cycle'eas oil collected in the ease as describedbelow maybe pass d through line 55 bymeans of' pump fi and introduced into the inlet of the coil of heater 51. wherein it is subjected to elevated conditions of temperature and pressure to effect cracking of the cycle stock to lower boiling products including gasoline constituents of high anti-knock value. and with minimum deposition of coke.

Reduced crude collected in the bottom of tower 42 is withdrawn therefrom through line 58 by means'of pump 59, and all or a portion thereof may be introduced into the coil of heater 5! at one or more points intermediatethe ends thereof, or all or a portion of the'reduced crude in line 53 may be diverted therefrom through line 65 and introduced into the coil of heater 5| at one or more points intermediate the ends thereof, or all or a portion of the reduced crude passing through line 58 may be diverted therefrom through line GI and introduced into the coil of heater 54 at one or more points interme- 7 heated prior to such introduction, and the pro portion thereof introduced into the coil and the degree of heating of the merged products thereafter is controlled to effect rather drastic cracking of the reduced crude .with production of lighter products therefrom including. gasoline constituent of high anti-knock value.

A'strea'm of normally gaseous hydrocarbons which preferably predominates in the C3 and/ or C4 hydrocarbons and which-may be suitably produced in the system as described below is passed through line 64. When reduced crude is being introduced into the coil. or heater 51 through line'58 all or a portion of the normally'rgaseous hydrocarbons in line 64 are diverted therefrom through line 55 which connects withthe coil of heater 51 at one orrnore points whereby the normally gaseous hydrocarbonsare introduced into admixture with the light and heavy oil undergoing treatment therein. The introduction of the normally gaseous hydrocarbons into the coil of heater 5'! is arranged to provide admixture of the normally gaseous hydrocarbons and the oils undergoing cracking before and/or after the light oil has undergone substantial conversion but prior to subjection of the heavy oil or reduced cru'de'to drastic cracking conditions for any substantial period. The presence of the convertible normally gaseous hydrocarbons in the merged products undergoing cracking treatment in the coil of heater 51 tends to minimize the production and formation of coke due to the drastic cracking of the reduced crude and promotes reactions between the normally gaseous.

hydrocarbons and conversion products thereof with conversion products of the liquid hydrocarbons undergoing treatment with a resultant decrease in gas production and increase in liquid products in the gasoline boiling range as well as crackable hydrocarbons of high boiling range which can be converted to gasoline by further thermal treatment.

Similarly, at least a portion of the normally gaseous hydrocarbons passing through line 64 may be diverted through line 65 and/or line 61 for introduction into the coil of heater 5| and/or the coil of heater 54, respectively, at one or more points thereof when reduced crude is being introduced into the coil of heater 5| through line and/or into the coil of heater 54 through line 6|, respectively. Valves 68, 69 and 10 are provided in lines 65, and6'l, respectively, to effect any desired diversion or distribution of the normally gaseous hydrocarbons from line- 64. The normally gaseous hydrocarbons may be preheated as desired prior to introduction into the coils of heaters 5| 54 and 51 by any suitable means as described below.

- The temperature and pressure in the coils of heaters 5|, 54 and 51 are maintained to effect substantial conversion of the relatively light oil introduced into the coils at the inlets thereof prior to admixture with heavy oil or normally gaseous hydrocarbons and to effect conversion of said heavy oil and said normally gaseous hydrocarbons to gasoline constituents of high antiknock value together with additional conversion of the relatively light oil as desired. For example, in heater 5| the heavy naphtha may be subjected to a temperature of 950 to 1050 F. at a pressure of 500 to 1000 pounds per square inch to effect reforming prior to admixture of reduced crude'or normally gaseous hydrocarbons therewith. After such admixture the merged products may be maintained at less drastic conditions, for example, at a temperature of 850 to 950. F. and at the same or lower pressure. In heater 54 the 'virgin gas oil may be subjected in the first part of the coil to a temperature of 900 to 1100", F. at a pressure of .200 to 1000 "pounds per square inch prior to introduction of the reduced crudeand normally gaseous bydrocarbons. After such admixture the merged products may be subjected to a temperature of 850 to 950 F. at the same or lower pressure. In heater5l cycle stock introduced through line 55 may. be subjected to. a temperature of 900 to 1075 F. at a pressure of 200 to 1000 pounds per square inch, and after any admixture therewith of reduced crude and normally gaseous hydrocarbonsthe merged products may be subjected to a temperature of 850 to 950-F. at the same or' lower pressure.

The cracked products from heaters 5|, 54 and 51 are withdrawn therefrom through lines H, 12 and 73, respectively, which connect with evaporator I4. Lines 15, 16 and 1'! connect lines 1|, 12 and 13, respectively, with a separate evaporator '18. Valves 19, 80, 8|, 82, 83 and 84 are provided in lines ll, 15, 12, I6, 13 and TI, respectively, to effect any desired reduction in pressure of the cracked products and the desired distribution thereof to evaporators l4 and T8.

. The distribution of cracked products from heaters 5| 54 and 51 isgoverned by the distributionof reduced crude and normally gaseous hydrocarbons for introduction into the coils. It is preferable to introduce cracked products containing products of the cracking of reduced crude into a common evaporator and to introduce cracked products free from products of cracking of reduced crude into a separate common evaporator. For example, cracked products from heaters 5|, 54 and 51 containingthe products of cracking of reduced crude may be introduced into evaporator 14 while such cracked products as are free of products of cracking of reduced crude are introduced into evaporator 18 by suitable manipulation of the valves as described above.

If desired, however, one evaporator may be used for the cracked products from all three of heaters SI, 54 and 51, and where each of these heaters is utilized for the cracking of reduced crude by introduction as described above the use of a single evaporator is sumcient. V j

It is advantageous, however, .tO provide a separate evaporator for cracked products from those heaters into a reduced crude has not been introduced for cracking treatment; since such cracked products will: ordinarily. contain naphtha of the higher anti-knock value whereas products of the cracking of reduced crude may contain substantial proportions of naphtha: of lower anti-knock value, audit; is advantageous from the standpoint of subsequent treatment and blending to have these two grades separated.

Evaporator 1- 4 isoperated to effect-passage overheadof vapors includingsuitable recycle material and the production of fuel oil which collects in the bottom thereof for withdrawal through line 8 5 providedwith control valve: 86; $uitable bafiiing may be arranged-in the top-- portion of evaporator Ht along with refluxing fac lities not shown toe-ffiect removal of en'-, trained matter from the vapor-s and permit the production of a. clean cycle stock in-fractioriator 28'. Evaporator H- may, forex-ample... be main taiiied' at. a pressure of 50 to 360V pounds per square inchand with. a bottom temperature of 50"to 850 B.

The vaporsiroznevapfirator 5 3 withdrawn" there 'ronr through line 8831111 3. are,.in 'oduced into frac ienator 9d. Ffrectionator is 1 p o: v ed w" h cooling means; 92 in the upper por- .and itis-operated-to-effect condcnsa d' collection in the bottomthereofi of a e cycle stock and. passage overhead of. a .-containingdistillate which-is withdrawrr through. line 93:. For example tractionator 56; may be operated at substantially the samepres-- sure as evaporator lav/1th; a. bottom temperature of 550t'e- 650 F. a top temperature of 350 to 425? p p p The trap-out tray 3-5 previded a -suita-b'lef piace in fractionator 99: to-efiectcollecticnaofi ai hewky naphtha condensate which may be withdrawn therefrom through line 95 provided" a control valve 91? for introduotien: into lined!! and" passage to reforming heater- 53; Suitable gas-and lifquid' contact means are provided in. fractionator 95' to efiectthe condensation and evaporationincidental to fractionation.

The cycle condensate collected in the bottom of fi'actionator 9B is withdrawn; thcrefrorrr through line 55 provided with control valve-398 and introduced into the. coil of heater 5:?v by means of pump 56; as described above.

Evaporator 7Smay be: operated under conditions comparable to those in evaporator 74 to effect the passage overhead of vapors including suitable recycle constituents. Suitable bafiiing' may be provided in the upper portion thereof along with refluxing facilities to efiect removal of entrained material from the Vapors. Liquids separated are removed through line 99 provided with valve m3.

Uncondensed vapors from evaporator I8 pass overhead through line I06 and are introduced into fractionator I s2. Fractionator I62 is provided with cooling means I94 in the upper portion thereof and is operated under conditions of temperature and pressure to efiect condensation of a suitable cycle stock which collects in the bottom of fractionator I02 and passage overis withdrawn through line 95. For eXample,-, iractionator H52 may be operated at ap pro mately thesame pressure evaporator fig; with a bottorntemperature of 55o to 650.F. anda top temperature of 350 to 450 F. Fraetionator I92 is provided withsuitabl-e gas and-liquidcontact means to e-fl'ect-the desired fractionation. V I

I'h e cycle stock is withdrawn from the lowerportion of i'ractionator IDZthrough line I91 pro-- 7 re bdwhereby the cyclestoekvfrorrr fract 01 s iant? 59-2 may be combined for pas; sageto i iet of the coil of heater ETI.

'lhe s and accompanying normal'iy gas-t eous cons.-tuents passing'overhead through fines as and are passed through condensers iii; i -ii, respectively,- wherein theyare cooled to eldest condensation of gasoline con StitUiGhb-Sz. The resulting mixtures of liquids and gases are passed through lines N2, M3- and H4;

respectively, to-separato1is i F5; I! 6 and I FI- where: in separation ofthe gases and liquids occurs: The liquids may be withdrawnpfrom separators I I5, H 5 and II'Itl-rrouglr lines H 8; I re andrllii, res vely,provided withcontroi valves tl ti -3 for separzimetrea-tment;v or draw-1on3 line's His, 5 35 and Ids provided with control valves til-5,. I 23 and V i 2iand connecting with-common line's: may be providedco effect biendin'g'. of the various gasoli nesin any desired proportion in line I3 5 through suitable manhmzlation of:

valves I21, I29 and i291,

Uncondensed gases-separatedeinseparators H 5, I

, passage through; line 6-4- for introduction intw heaters.- 54, t tan-d 5% as described-above; s a? condensate which collects in the bottorrrofi nae: tionator.- E38;

preheated if desired through" heat ex h-arig'ewith th-e'gases in liner in'heat' exchanger l dfiw ith thev'apors-passing thmugh line harshest e's I changer Iii iguand'with' the vapors p'assihg' throng-h line 93 in heat exchanger I42.

tionator 1'38 to effect the desired; fractionation. Forve xample; fractionator I38 may be operated at a pressure of 300 to 350 pounds per square inch with a bottom temperature of to F, and a top temperature of 30 F. It may, under some circumstances, be advantageous to fractionate the cracked gasoline issuing from line I38 to free it from all hydrocarbons below the C5 series and to return the lighter hydrocarbons so produced to fractionator I38 along'with the gas from line I31. I

Preferably, the condensate collected in the' bottom of fraction'ator I38 predominates in the C3 and C4 hydrocarbons which are most susceptible to conversion to gasoline constituents in heaters EI, 54 and 51. The uncondensed gases head of a gasoline-containing distillate which Y vld ed with control valve: I68 which line connects: I

This :condehsaite is" warfare-war a through Iine-M-byTmeansOf pump l'fi 'arrd pas w to heaters: 54', 5d and W asdesired after being are withdrawn through line M provided with control valve 14?. The relatively low temperature of gases passing through line I46, especially after expansion through valve Hi7, may be utilized in any suitable manner in the operation of fractionator 138.

It is to be understood, of course, that the gases passing through line 13? may be used as such for introduction into the coils of heaters 5!, 5'3 and 5'! through line 84. For example, line lfiil connecting line'lBl and line 64 may be provided to divert all or a portion of the gases around the fractionators 138 and pass them directly to the heaters. Valves l5l and IE2 may be provided in lines I50 and [37, respectively, to effect the desired distribution of gases.

'While the coils of heaters Si, 54 and 51 are illustrated as being housed in separate structures it is to be understood, or course, that they may constitute separate coils each located in a furnace structure which may also house one or more other coils. For example, the coils of heaters 5|, 54 and 51 may be arranged in a single heater in the parts thereof wherein they are subjected to the desired applications of heat. Furthermore,

the various portions of eachflcoil may be arranged in different parts-cf the furnace whereby each portion receives the desired application of heat depending upon its function as a heating or reaction zone or both. It is also to be understood that although the figures herein show all conversion and reactions to be effected in the coils of the heaters separate reaction chambers may alternately .be employed for maintaining the hydrocarbons under the proper conditions for the necessary lengthof time.

It is to be understood also that the relative proportions of the various-intermediate products returned to the system may vary within wide limits,':and any portions undesired for further treatment in the system may be withdrawn therefrom by separate means which are omitted from the drawing'forpurposes of simplification. Furthermore, additional materials similar to the intermediate products produced in the system may be introduced for use incombination with such intermediate products to remedy any deficiency thereof. It is to be further understood that the materials charged to the heaters may be preheated to any desired temperature by any necessary means not shown andthat the cracked products therefrom may be cooled prior to evaporation by any suitable means such as heat exchange with cooler products produced elsewhere in the system. V

. The present invention thus provides a suitable means forthe treatment of a plurality of hydrocarbons of different boiling ranges by relatively simple means and under conditions of maximum efficiency to effect maximum conversion thereof into motor fuel of high anti-knock value. The more specific advantages of the present invention are clearly apparent; from the foregoing description. a

It is to be understood, however, that the descriptions in reference to specific apparatus are merely for purposes of illustration, the'inventionbeing capable'of other embodiments which may be beyond the-physical limitations of the apparatus illustrated.

Iclaim: a

The method of treating hydrocarbons to produce therefrom motor fuel of high anti-knock value which comprises fractionating'crude oil to separate therefrom a light naphtha distillate, a heavy naphtha condensate, a virgin gas'oil condensate and a hydrocarbon oil higher-boiling than said virgin gas oil, passing said gas oil'through a single pass cracking zone wherein the gas oil is-separately subjected to cracking conditions of temperature and pressure to eifect cracking thereof to lighter products comprising motor fuel constituents of high anti-knock value, fractionating resultant conversion products in a fractionating zone to obtain a residue, a reflux condensate, a desired motor fuel distillate and normally gaseous hydrocarbons predominating in hydrocarbons heavier than ethane, separately subjecting said heavy naphtha condensate, obtained in fractionating the crude oil, toreforming conditions of temperature and pressure to effect conversion thereof to motor fuel constituents of high antiknock value by passage as a stream through a separate elongated heating zone of restricted cross-section, introducing into said elongated heating zone intermediate the ends thereof said normally gaseous hydrocarbons and said higher boiling hydrocarbon oil, obtained from the said crude oil fractionation, whereby said higher boiling hydrocarbon oil and said normally gaseous hy-' drocarbons are merged with said heavy naphtha in said zone after substantial reforming of the heavy naphtha has been effected, passing the merged products through the remainder of the heating zone under cracking conditions of temperature and pressure to effect conversion to motor fuel constituents of high anti-knock value, directing the resultant products of conversion to the aforesaid fractionating zone, passing refiux condensate from said fractionating zone to a separate recycling cracking zone wherein the reflux condensate is separately subjected to cracking conditions of temperature and pressure to effect conversion into motor fuel constituents and dirioting the resultant products of conversion to said fractionating zone for fractionation therein.

GEORGE ARMISTEAD, JR. 

